首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1102篇
  免费   148篇
  国内免费   49篇
耳鼻咽喉   9篇
儿科学   96篇
妇产科学   17篇
基础医学   99篇
口腔科学   44篇
临床医学   100篇
内科学   329篇
皮肤病学   29篇
神经病学   19篇
特种医学   189篇
外科学   65篇
综合类   98篇
预防医学   72篇
眼科学   9篇
药学   65篇
中国医学   3篇
肿瘤学   56篇
  2024年   3篇
  2023年   16篇
  2022年   13篇
  2021年   24篇
  2020年   21篇
  2019年   8篇
  2018年   19篇
  2017年   41篇
  2016年   37篇
  2015年   29篇
  2014年   63篇
  2013年   69篇
  2012年   24篇
  2011年   21篇
  2010年   62篇
  2009年   67篇
  2008年   25篇
  2007年   63篇
  2006年   31篇
  2005年   21篇
  2004年   19篇
  2003年   9篇
  2002年   8篇
  2001年   28篇
  2000年   12篇
  1999年   16篇
  1998年   77篇
  1997年   64篇
  1996年   59篇
  1995年   50篇
  1994年   45篇
  1993年   42篇
  1992年   12篇
  1991年   6篇
  1990年   16篇
  1989年   21篇
  1988年   25篇
  1987年   15篇
  1986年   19篇
  1985年   18篇
  1984年   9篇
  1983年   14篇
  1982年   9篇
  1981年   4篇
  1980年   8篇
  1979年   4篇
  1978年   6篇
  1977年   5篇
  1976年   12篇
  1975年   9篇
排序方式: 共有1299条查询结果,搜索用时 0 毫秒
31.
32.
33.
34.
35.
A group of unique Epstein-Barr virus-containing cell lines was derived from the bone marrow of three patients with X-linked agammaglobulinemia. Efforts to obtain cell lines from the peripheral blood of these patients were uniformly unsuccessful. Immunofluorescence analyses as well as biosynthetic studies with [(35)S]methionine indicated unusual patterns of Ig synthesis in many of these bone marrow derived lines. Seven of the lines were of particular interest in that two produced no Ig of any type; two others showed no Ig by fluorescence but small amounts by [(35)S]methionine labeling; one expressed only cytoplasmic μ chains without any evidence of light chain synthesis, and two produced primarily μ chains with only slight amounts of light chains. One of the lines without membrane or cytoplasmic Ig studied in detail grew like a typical lymphoid line and was carried in intermittent culture over a period of 2 yr without Ig expression. One line grew quite differently and resembled the round cell type described previously, which has been obtained from a variety of sources. The cell line with cytoplasmic μ chains and no light-chain expression had the characteristic properties of pre-B cells. Three normal type Ig-producing cell lines also were obtained from the patients. The accumulated evidence obtained in the present study indicates that these unusual cell lines represent normal precursor cells of the B-cell lineage; these grew out in these cases because of the virtual absence of mature B cells that ordinarily overgrow the culture system. However, the possibility that in certain instances they reflect abnormal Ig synthesis characteristic of the disease has not been ruled out.  相似文献   
36.
37.
Oral Diseases (2010) 16 , 686–695 Objective: This study was designed to test the hypothesis that periodontal pathogens Tannerella forsythia and Porphyromonas gingivalis are synergistic in terms of virulence potential using a model of mixed‐microbial infection in rats. Materials and methods: Three groups of rats were infected orally with either T. forsythia or P. gingivalis in mono‐bacterial infections or as mixed‐microbial infections for 12 weeks and a sham‐infected group were used as a control. This study examined bacterial infection, inflammation, immunity, and alveolar bone loss changes with disease progression. Results: Tannerella forsythia and P. gingivalis genomic DNA was detected in microbial samples from infected rats by PCR indicating their colonization in the rat oral cavity. Primary infection induced significantly high IgG, IgG2b, IgG1, and IgG2a antibody levels indicating activation of mixed Th1 and Th2 immune responses. Rats infected with the mixed‐microbial consortium exhibited significantly increased palatal horizontal and interproximal alveolar bone loss. Histological examinations indicated significant hyperplasia of the gingival epithelium with moderate inflammatory infiltration and apical migration of junctional epithelium. The results observed differ compared to uninfected controls. Conclusion: Our results indicated that T. forsythia and P. gingivalis exhibit virulence, but not virulence synergy, resulting in the immuno‐inflammatory responses and lack of humoral immune protection during periodontitis in rats.  相似文献   
38.
39.

Aims

The management of patients with in‐stent restenosis (ISR) is still a major clinical challenge even in the era of drug‐eluting stents (DES). Recent studies have demonstrated acceptable clinical outcomes for the everolimus‐eluting bioresorbable vascular scaffold (BVS) ABSORB? in patients with stable coronary artery disease but data are scarce on its use in patients with ISR. We report the long‐term results of our preliminary experience with this novel approach at our institution.

Methods and Results

We investigated the safety and efficacy of BVS implantation to treat ISR. 34 consecutive patients (37 lesions) underwent PCI for ISR with BVS implantation between May 2013 and June 2015 at our institution and were included in the current analysis. Follow‐up was available in 91.9% of the patients. Mean follow‐up period was 801.9 ± 179 days. One patient had definite scaffold thrombosis (ScT) 2 months after stent implantation which was treated with DES. Five patients (six lesions) experienced target lesion revascularization (TLR). The composite endpoint rate of TLR, ScT, myocardial infarction, and death occured in 6/37 lesions at follow‐up (16.2%).

Conclusions

These real‐world data using BVS in patients with ISR demonstrates that ISR treatment with ABSORB? BVS is feasible but could have slightly higher target lesion failure rates as compared to DES. This proof of concept could be hypothesis‐generating for larger randomized controlled studies.
  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号